Closure element for absorbent sanitary product, manufacturing process, process of use, and product thus obtained

ABSTRACT

A fastening element for absorbent sanitary products having first and second parts that are symmetrical with respect to an intermediate plane, each part including a base branch configured to connect to the first part, and a distal branch configured to connect to the second part. The base branch and the distal branch are connected together according to a general book-like configuration. A dorsal part of the book-like configuration for connection between the base and the distal branches is set at a distance from said intermediate plane, the base branch connects the two parts to form a single body, each of which can connect mutually facing edges of the end parts of an absorbent sanitary product and to ensure the fastening of the flaps set on the sides. The fastening element can enable releasing and refastening the product and/or adjusting the fit of the product to the wearer&#39;s body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to absorbent sanitary products and hasbeen developed with particular attention paid to its possibleapplication to absorbent sanitary products that can be worn like a pairof pants. A typical example of absorbent sanitary products of this typeis represented by baby diapers or the like.

2. Description of the Related Art

For many years now, the solution adopted in a practically uniform way byall the manufacturers of the sector has been that of making theseproducts in the form of elements shaped according to a general hourglassconfiguration, with a central body, in which there is provided acomposite absorbent structure designed to absorb body fluids, and twoend parts, a front one and a rear one, which extend laterally. Theproduct is put on, bestowing on it a general U-shaped configuration andbringing the median stretch of the central body up to the area where thelegs of the user are inserted. The end parts are extended around thewaist of the user, connecting the mutually opposed side edges thereoftogether by means of adhesive labels or stickers, which can normally bere-positioned, or similar fastening elements in such a way as to be ableto refasten the product around the body of the user.

These products have been traditionally manufactured and sold in the opencondition, i.e., leaving to the person who applies the product the taskof setting it around the body of the user and of fastening it accordingto a general pant-like conformation in the way referred to previously.

In the course of the last few years, there has emerged a renewedinterest in diapers of the type commonly referred to as “trainingpants”. These are diapers of the type illustrated, for example, in thedocument U.S. Pat. No. 4,610,680, which are designed for being packagedand sold in a closed condition. When the product is taken out of thepackaging, it has a conformation basically resembling that of a pair ofpants. It is put on by making it slide over the legs of the useraccording to criteria basically similar to those followed for putting ona pair of pants. In view of the specific use to which the product is tobe put, it is then envisaged that the product can be removed withouthaving to slide it again over the legs of the user.

For this purpose, the product can be made in such a way as to betearable (according to the criteria illustrated, precisely, in U.S. Pat.No. 4,610,680), or else by making the product so that it can be openedalong the sides of the waist line, i.e., in an area of what may bedefined the side flaps (as in the case of diapers of a traditional type,which are packaged and sold in the open condition), for example byenvisaging the use of adhesive labels or stickers, sets of buttons, setsof press-studs or, according to a solution that has enjoyed a particularsuccess, by envisaging the use of microhook fastening structures (alsoreferred to as “Velcro fasteners”).

The use of such fastening elements must be reconciled with the need, towhich reference has already been made previously, to have the trainingpant preferably produced and packaged in a closed condition, so as toenable it to be put on like a normal pair of pants.

Various patent documents deal with the problem of applying thesefastening elements in the framework of an industrial cycle that can beimplemented In a context compatible with the high production rates thatare typical of the sector.

In this connection, reference may be made, for instance, to thedocuments U.S. Pat. Nos. 5,855,574, 6,210,388, 6,409,858, 6,477,628, andU.S. Pat. No. 6,461,344.

The above documents, which do not, however, exhaust the entire field onthe subject, deal with the problem of the application of the aforesaidfastening elements by drawing particular attention to the functionalityof the end product.

At least some of these documents of course take into account the need tomake the corresponding products at typical industrial production rates.For this reason, they suggest, according to different modalities,resorting to production processes of a continuous type, in which theproducts are made starting from the individual component parts,operating preferentially on a continuous chain of products designed forbeing separated from one another, so as to arrive at the formation ofthe individual products only in the final stages of the process.

However, above all as regards the application of the aforesaid fasteningelements, the solutions described in these prior documents do not takeinto account various problems that can assume a considerable importanceboth at the level of manufacture and at the level of use of the productsin question.

In the first place, during fabrication of the sanitary product, in theprocess of apply a fastening element (or a part of said element) on astrip, web or chain, the aforesaid strip, web or chain moves along at arelatively high linear speed, and may expose the aforesaid element, whenit is not completely anchored to the strip, web or chain on which it isapplied, to flap or move. Movement of the strip during fabrication maycause the element itself to be positioned improperly for subsequentoperations of treatment, in particular as regards possible operations ofcutting.

Furthermore, it is necessary to take into account the fact that thecutting operation for separating the individual sanitary products or thetype of connection of the side edges used, can lead to the formation ofelements or surfaces of friction which, if not appropriately shielded,may give rise to even rather disagreeable drawbacks, for instanceirritation or cutting of the skin, since they directly face the body ofthe user.

Furthermore, it is important to prevent the user (typically, forinstance, a baby, perhaps even a very small baby) from possibly opening,with the application of even a modest force, the flaps set on the sidesand causing undesirable release of the fastening element, in particularin the case of absorbent products designed to be refastenable.

BRIEF SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fastening elementthat is able to solve at least one and, in the currently preferredembodiments, all of the problems outlined above.

According to the present invention, this purpose is achieved due to afastening element having the characteristics recalled specifically inthe claims that follow.

The invention also relates to a corresponding process of fabrication anda corresponding method of use in order to obtain an absorbent sanitaryproduct. As will emerge more clearly from what follows, the said processand method are suited for being possibly integrated together and forbeing carried out one after another in the sequence of a single process.Finally, the invention also regards the absorbent sanitary product thusmade.

In the currently preferred embodiments, the fastening element accordingto the invention is configured as a sort of closed packet, without foldsor similar configurations, which can be opened at the moment of cutting,transfer and positioning of the element on the structure of absorbentarticles, such as diapers.

The above is possible thanks to the particular shape adopted, which ispreferably an omega shape (and which preferably envisages the use of asingle type of material for the main constituent element), with theadded possibility of applying provisional seal formations, which can beremoved during use of the product, for better conservation duringmanufacture of the closed-packet structure referred to previously.

The solution described leads to the production of a fastening element,which, thanks to the structure and to the material used for the mainconstituent element, makes it possible to achieve a continuous anddelicate contact or feel (the so-called “soft touch”) on the hips of theuser so preventing any risk of causing irritation or cutting of theskin.

In addition, the solution described herein enables production of anabsorbent sanitary product with flaps set on the closed sides by meansof releasable elements, for example of the microhook (hook-and-loop),e.g., Velcro, type, or re-openable seal formations, for instance glue ofthe “evergreen” type (i.e., a glue which preserves its qualities overtime, even following upon repeated detachment-reattachment of theconnected parts), this glue also being referred to as“pressure-sensitive” glue, in which there is altogether prevented theeventuality of the user possibly forcing, by getting hold of any freeflaps, the connection between the parts of the fastening element (inparticular in the versions in which said fastening element isrefastenable), so causing undesirable opening of the product.

It is important to note that in products of this sort, in which theflaps set on the sides of the product are not closed by means ofre-openable elements, in order possibly to release and refasten theproduct it is necessary to tear the flaps.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention will now be described, purely by way of non-limitingexample, with reference to the annexed drawings, in which:

FIG. 1 is a cross-sectional view of a fastening element according to afirst embodiment of the invention;

FIG. 2 illustrates the fastening element of FIG. 1 applied on twosanitary products comprised in a chain of products in the course ofmanufacture;

FIG. 3 illustrates the fastening element of FIG. 1 in its typicalconfiguration of use, with the flap located on the sides closed;

FIGS. 4 to 6 illustrate, according to modalities respectivelycorresponding to the criteria of representation adopted in FIGS. 1 to 3,another embodiment of a fastening element according to the invention;

FIGS. 7 to 9 illustrate, once again according to criteria basicallysimilar to the criteria of representation adopted in FIGS. 1 to 3, athird possible embodiment of a fastening element according to theinvention;

FIGS. 10 to 12 illustrate a possible variant mode of fabrication of theembodiment represented in FIGS. 7 to 9;

FIGS. 13 to 15 illustrate, according to criteria basically similar tothe criteria of representation adopted in FIGS. 1 to 3, yet anotherembodiment of a fastening element according to the invention;

FIGS. 16 to 18 illustrate a possible variant mode of fabrication of theembodiment represented in FIGS. 13 to 15;

FIGS. 19 and 20 are schematic representations in perspective view of twopossible solutions embodying equipment which, on the one hand, providesfastening elements according to some of the embodiments of the presentinvention and, on the other, applies the fastening elements thusproduced on a chain of absorbent sanitary products that are beingformed;

FIGS. 21 and 22 are schematic illustrations of possible alternativeembodiments of the solutions illustrated in FIGS. 19 and 20; and

FIGS. 23 to 25 illustrate a still further possible variant mode offabrication of the embodiment represented in FIGS. 16 to 18.

DETAILED DESCRIPTION OF THE INVENTION

In the various representations of FIGS. 1 to 18 and FIGS. 23 to 25, thefastening/closure element described herein is not drawn to scale. Thisfact can be appreciated e.g., by direct reference to FIGS. 19 and 20 andcorresponds to a deliberate choice made for the sake of clarity ofpresentation.

With immediate reference to FIGS. 19 and 20, in these figures thereference D indicates absorbent sanitary products such as diapers of thetype commonly known as training pants.

FIGS. 19 and 20 refer to products made by operating crosswise.

This latter mode of operation, which is to be deemed known in its mostgeneral terms, envisages making a strip, web or chain of sanitaryproducts (or, more correctly, of semi-finished pieces D′ of saidproducts), each of which presents a general hourglass configuration.

The semi-finished pieces D′ are constituted by:

-   -   a top or inner sheet (i.e., with respect to the normal        conditions of use of the diaper), usually referred to as        “topsheet” (TS), on which there can be set a pair of elasticized        lateral barriers, which extend from one of the borders of said        topsheet to the opposite border, and a pair of elastic or        elasticized formations set centrally on the ends of said        borders, in the direction orthogonal to said elasticized        barriers;    -   a backsheet (BS), i.e., a bottom or outer sheet or laminate        (with respect to the normal conditions of use of the diaper), on        which there may be set a pair of elastic or elasticized        formations that extend from one of the borders of said backsheet        to the opposite border; and    -   an absorbent structure enclosed between said topsheet and said        backsheet.

In the various FIGS. 2-3, 5-6, 8-9, 11-12, 14-15 and 17-18, thebacksheet and the topsheet are designated, respectively, by thereferences BS e TS. The references TS and BS also appear in FIGS. 19 and20.

The general hourglass configuration of the semi-finished pieces D′ isthe result of the generically widened pattern of the lateral end partswith respect to the sides of the central portion (or the area thatremains adherent to the body) of each sanitary product, in which thereare present parts S, which are cut out according to a general archedpattern (i.e., the cuts where the legs are inserted). Briefly, these arethe parts which, in the diaper D closed to form a pair of pants,constitute the openings for the legs of the user (or passages for legs).

As is well known to persons skilled in the sector, the elastic orelasticized formations arranged centrally on the ends of the borders ofthe topsheet have the purpose of ensuring adherence of the waist line ofthe diaper to the abdomen of the user, whilst the elastic or elasticizedformations which extend from one of the borders of said backsheet to theopposite border have the purpose of ensuring adherence of the passagesfor legs to the legs of the user.

The lateral end parts of the various semi-finished pieces D′ areconnected together so as to form the chain, strip or web alreadymentioned previously. For this reason, in the chain of semi-finishedpieces D′ represented at the bottom left in FIGS. 19 and 20, the cut-outparts S of the semi-finished pieces D′ adjacent to one another areconnected together to form, in the otherwise continuous body of thechain itself, approximately elliptical openings.

In a folding station 100, the chain of semi-finished pieces D′ undergoesfolding to form a V in the central region or adherent area of thehourglass configuration.

The operation of folding to form a V brings the opposed longitudinalmargins F1 and F2 of the chain to overlap one another so as to form(according to criteria described more clearly in what follows) the waistlines of the individual products D. Simultaneously, the cut-out parts Scome to form the passages for the legs in the products themselves.

The chain of products finally undergoes a cutting operation, implementedfor example in a cutting station, designated by 102, which has arotating-blade cutter. The cutting station 102 operates along the lineidentified by X-X in FIGS. 19 and 20 (the same indication appears—forreasons that will emerge more clearly from what follows—also in FIGS.1-2, 4-5, 7-8, 10-11, 13-14 and 17-18). The cutting action brings aboutseparation of the products D, which thus assume the character ofindividual products, which are to be sent on to a packaging station (notillustrated).

The general criteria for carrying out the operations just described arein themselves known in the prior art and do not require a detaileddescription herein, except as regards the elements that assume specificimportance for the purposes of an understanding and implementation ofthe invention.

Persons skilled in the sector will understand that the characteristicsand the modalities of application of the fastening elements 1, whichwill emerge more clearly from what follows, are to a large extentindependent of the specific characteristics of embodiment of the variousproducts D. This applies, in particular, but not exclusively, as regardsthe structure (or “construction”) of the product D, i.e., as regardscharacteristics, such as the composition of the backsheet BS and of thetopsheet TS and of the layers and auxiliary formations normallyassociated thereto, etc.

The fastening elements 1 described in what follows, in the embodimentsrepresented in FIGS. 1 to 6, may be used in diapers of a training-panttype, which, once they have been brought into the closed position,cannot be re-opened unless they are torn.

In the other embodiments represented—and in particular in theembodiments represented in FIGS. 7 to 9, which constitute the currentlypreferred embodiments of the invention—the fastening elements enableimplementation of the function of release and refastening of the diaper,this being according to modalities that enable identification of thefastening element as releasable and refastenable.

It is to be noted how all the fastening elements 1 described enablediapers of a training-pant type to be made, which are characterized inthat the flaps are set on the sides, in the normally closed condition,but are releasable and refastenable so as to enable access to thefastening elements in the case of diapers of the training-pant type (inwhich the fastening elements are of the releasable and refastenabletype) and the subsequent fastening of the flaps themselves. In this way,since it is possible to prevent tearing of said flaps, and consequentexposure of the fastening elements of the releasable and refastenabletype, any undesirable release of the diaper by the user is prevented.

The fastening elements 1, which are described more clearly in whatfollows, are designed for being located precisely in the areas ofconnection between the facing ends of two adjacent products D.

In FIGS. 19 and 20, the ends in question are designated, respectively,by B1 and B2 with reference to the (single) product D represented in thepart furthest to the right in FIGS. 19 and 20, at output from theequipment illustrated herein. Furthermore, also designated by B2 is theend further downstream of the immediately adjacent product D.

Since the products D derive from the operation of folding to form a Vperformed in the station 100, each reference B1 and B2 actuallyidentifies a pair of end borders (each corresponding to one of themargins F1 and F2 of the original chain constituted by the semi-finishedpieces D′ shaped like an hourglass).

As will emerge more clearly from what follows, the elements 1 have thefunction of connecting the end borders comprised in each of theaforesaid pairs, fastening the waist line of the respective products Dfollowing upon fastening of said end borders.

When the chain of products D illustrated in FIGS. 19 and 20 undergoescutting along the line X-X in the station 102, the elements 1 are alsocut along a median or basically median plane, thus being divided intotwo parts or halves.

Of these halves, a first half remains associated to the end B1 of aproduct D, by connecting the two corresponding borders, and a secondhalf remains associated to the end B2 of the immediately adjacentproduct, also in this case by connecting the two corresponding borders.

If attention is paid precisely to the latter product D, which may beseen in the part furthest to the right in FIGS. 19 and 20, it may beunderstood how the fastening of the waist line of the product inquestion is ensured, at the end B1, by the first half of an element 1and, at the end B2, by the second half of another element 1, which hasbeen previously cut in the station 102.

Likewise, in the product D that immediately follows (namely, the onewhich, in FIGS. 19 and 20, appears as still undergoing the action of thecutting unit 102), the fastening of the waist line is ensured, at theend B2, by the second half of the element 1, the first half of whichcloses at the end B1 the product D further downstream and, at the end B1(not, in actual fact, visible in the drawings in so far as it is hiddenby the cutting unit 102), by the second half of another element 1, whichis currently undergoing the action of the cutting unit 102.

The elements 1 can thus be used in a process for making sanitaryproducts D, which can be worn like a pair of pants and which compriseopposed ends, which can be selectively connected to respective bordersso as to define the waist line and the passage for legs of the sanitaryproduct.

The process envisages, for this purpose, the operation of forming achain of semi-finished pieces D′ of absorbent sanitary products, inwhich semi-finished pieces that are adjacent in the chain are connectedto one another at the aforesaid ends so as to form connection regionsbetween successive semi-finished pieces in the chain. The saidconnection regions each have a centre line (X-X), which extends in adirection transverse to the principal direction of extension and ofadvance of the chain of semi-finished pieces of sanitary products D′.

The fastening elements 1 are then applied (as will emerge more clearlyfrom what follows) in the aforesaid connection regions, so causing themedian plane of each fastening element 1—i.e., the plane which is alsodesignated by X-X for immediate reference—to be aligned with the centreline of a corresponding connection region.

The aforesaid semi-finished pieces of sanitary products are thenre-closed on themselves according to a general V-shaped (or U-shaped)configuration, bringing the end parts of the semi-finished pieces into aposition where they are facing one another with the interposition of thefastening elements 1.

The chain of semi-finished pieces of sanitary products is finallysegmented along the centre lines of the connection regions, so causingcutting of the fastening elements in their median plane X-X, with thecorresponding division of the fastening elements into the aforesaid twoparts or halves, which are basically symmetrical with respect to oneanother. These remain in their position, thus ensuring fastening of thewaistline by means of closing of the side edges of the two individualproducts separated by the cutting action.

The first embodiment of the fastening element 1 represented in FIGS. 1to 3 practically corresponds to a base configuration.

The fastening element 1 represented in FIG. 1 is basically constitutedby a strip of laminar material, such as a non-woven fabric, for instanceof the type commonly referred to as SMS, folded according to a generalomega-shaped configuration.

In practice, the element 1 in question comprises:

-   -   a base branch 10, which extends in a basically symmetrical way        around the ideal line X-X along which the element 1 is then to        be cut in the operation of separation carried out in the cutting        station or cutting unit 102 described previously;    -   two intermediate branches 12, each of which is folded on the        base layer so as to return towards the line X-X (without        reaching it, to prevent undesirable effects of cutting, when the        fastening element 1 is divided into two halves along the plane        X-X); and    -   two distal stretches 14 turned up again on the intermediate        stretches 12 so as to extend with their end borders        approximately at the outer borders of the base branch 10 and of        the loops or elbows that connect the intermediate stretches 12        with the borders of the base branch 10.

Of course, the choice of making the distal stretches 14 extend withtheir end borders approximately to the outer borders of the base stretch10 is not to be considered in any way imperative. The distal stretches14 can in fact be made so that they are both of equal length, eithershorter or longer as compared to the corresponding portions of the basebranch 10. The same also applies to the intermediate stretches 12.

The reference 16 designates a layer of glue designed to render theintermediate branches 12 fixed to the homologous parts of the base layeror base branch 10. It may, for instance, be a layer of glue of thehot-melt type or any other type commonly used for the connection oflaminar products, such as, precisely, non-Woven fabrics in thesanitary-products industry.

The reference number 23 designates provisional-seal formations that canrender the intermediate stretches 12 fixed to the corresponding distalstretches 14. These provisional-seal formations can be made with theapplication of spots of evergreen or pressure-sensitive glue or by meansof welding spots of a thermo-mechanical type (heat sealing).

Essentially, the fastening element just described comprises two parts orhalves, which are basically symmetrical with respect to a median planeX-X. Each of these two parts in turn comprises a base-branch portion 10and a distal branch 14 connected together according to a generalbook-like configuration, which is open towards the outside of theelement 1 by means of the intermediate stretch 12.

The base branch 10 connects together the aforesaid two basicallysymmetrical parts so as to form a single element that can be cut alongthe median plane X-X in order to separate said two basically symmetricalparts.

In this connection, it will be appreciated that the elbow parts—i.e.,the backs of the book-like configurations—which connect the base branch10 (and each intermediate branch 12) to the distal branches 14—are setat a distance from the median plane X-X precisely so as not to beinvolved in the cutting operation performed in the station 102 of FIGS.19 and 20.

The arrangement is such that the element 1 may be applied with theaforesaid two basically symmetrical parts or halves applied on facingborders of homologous end parts of two of said sanitary products Dadjacent to one another in a strip or chain of formation (in thisconnection see once again FIGS. 19 and 20).

Cutting in the plane X-X, carried out for example in the unit 102illustrated in FIGS. 19 and 20, separates the two parts or halves of theelement 1, leaving them applied, respectively, on one and on the otherof the facing ends of two successive products D in the chain offormation.

The fastening element thus obtained can be made in the form of aprefabricated intermediate product (both as regards the generalomega-shaped folding, and as regards the application of the glue 16 and,possibly, of the provisional seal formations 23) prior to itsapplication on the sanitary product.

The fastening element 1 can be made in the form of a strip wound inreels and designed to be unwound towards the region where application onthe products D is performed.

The application of the element usually entails the use of two layers ofglue of the type commonly adopted in the industry of sanitary productsaimed at anchorage of the connection element on the facing borders ofthe homologous lateral end parts of two sanitary products D with,preferentially, application of a third layer of glue in order to fastenthe flaps set on the sides of the diaper.

The types of glue considered may be either identical or different fromone another.

For example, the glue may be, in the case of the first two layers, ofthe hot-melt type and, in the case of the third layer, of the evergreentype.

In this case, the first layer of glue, designated by 18, is a virtuallycontinuous layer, which connects the base branch 10 of the element 1 toone of the front ends (the choice between front and rear is hot initself binding) of the product D.

The second layer of glue, designated by 20, is usually divided into tworegions or areas, each of which connects one of the distal branches 14of the fastening element 1 to the opposite side end of the product D.

The third layer of glue, designated by 25, is made (usually withevergreen glue: i.e., a glue which preserves its qualities over time,even following upon repeated detachment-reattachment of the connectedparts) in the region or area delimited by the projection of the edges ofthe elbows that connect the intermediate stretches 12 to the distalstretches 14 on the side end of the product D opposite to the basebranch 10.

Upon cutting of the chain of products D along the line X-X, the layer ofglue 25 is able to favor adhesion (releasable and refastenable adhesion,if the glue is of an evergreen type) between the topsheet/backsheet ofone of the lateral end parts of the product D and the central portion ofthe base branch 10 of the connection element.

As will appear more clearly from FIG. 3, after cutting and splaying-outof the product D, the line of connection with evergreen glue 25 extendsto closing of the outer stretch of connection between the two lateralend parts of the product D, so preventing discontinuity of any sort andhence achieving (releasable and refastenable) fastening of the flaps seton the sides of the diaper.

In an alternative embodiment, at least one of the layers of glue 18 or20 may consist of a glue with a degree of adhesion that is sufficientlyhigh as to ensure firm and secure fastening of the product along thewaist line in the conditions of normal use, but at the same time such asto enable removal of the product (for instance, once that it has beensoiled) by opening it precisely in a position corresponding to thefastening element, which in this case functions, so to speak, aspreferential tearing region.

Also in this case, the layer of glue 25 preserves the function describedpreviously.

It will again be appreciated that, in all of the configurationsdescribed, the layer 25, if it is made using evergreen glue, can beexploited for keeping the product that has been definitively removed andis to be thrown away packed tightly closed, this being substantiallysimilar to the procedure normally adopted in the case of adhesivestickers for disposable diapers of a traditional type.

The aforesaid configurations of connection can be obtained according tothe criteria that will be described more clearly in what follows withreference to FIGS. 19 and 20. It may be preferable to operate by causingthe element 1 to be applied on the product D by first making theconnection of the distal branches 14 to the corresponding end portion ofthe product D with the application of the layers of glue 20.

This latter solution presents the advantage that the element 1 thusapplied on the strip or web of products D will in any case be closed, inthe sense that the two end or distal branches 14 of the omega shape areboth firmly connected to the web of products D, without leavingprojecting parts that may flap in an uncontrolled way even though thechain or web moves at a rather high speed.

In each case, thanks to the provisional-seal formations 23, whicheverthe lateral-end part of the product D on which the element 1 isinitially applied, since the element itself may be likened to a closedelement, it is not in any case exposed to negative phenomena offlapping.

The element 1 can then be set exactly in place, without undergoingdeformation or creasing, in the subsequent application station, in whichthe bottom branch 10 is applied against the corresponding end part ofthe product D with the application of the layer of glue 18, after priorfolding in the form of a U of the products D.

FIG. 3 shows the end result of the operation of separation of thevarious products D, i.e., when the chain of products D (closed to form aV in the station designated by 100 in FIGS. 19 and 20, so that eachassumes the desired configuration of a pair of pants with the waist lineclosed by means of the fastening elements 1) undergoes cutting along theline X-X in the cutting station 102.

In practice, on each of the sides of the product D (just one of thesesides may be seen in the figure in question and in the other homologousfigures of the annexed drawings), the two opposite end parts of theproduct, corresponding to the flaps thereof, are connected togetheraccording to a general hinge-like configuration by one of the distalbranches 14 (connected to the respective end part of the product D bythe layer of glue 20) and by the homologous intermediate branch 12. Thelatter is connected to the respective end part of the product D thanksto the presence of the layer of glue 16. This layer of glue ensuresanchorage of the intermediate branch 12 to a corresponding half of thebase branch 10, which is, in turn, connected by a respective portion ofthe layer of glue 18 to the corresponding end part of the sanitaryproduct.

The intermediate branch 12 extends with continuity of connection to therespective half of the base branch 10. This gives rise to a particularlyfirm connection, and hence one that is able to withstand any tensilestress to which the fastening element 1 may be subjected during use ofthe product. It is here evident how the layer of glue 25 ensuresreleasable and refastenable fastening of the flaps located on the sidesand how the distal branch 14 and the intermediate branch 12 provide forshielding of the flap, ensuring a continuous and delicate contact (softtouch) on the hips of the user.

The alternative embodiment illustrated in FIGS. 4 to 6 is, as a whole,similar to the embodiment represented in FIGS. 1 to 3 so that thereapply thereto basically all the considerations made previously asregards the embodiment represented in FIGS. 1 to 3. The main differenceis represented by the fact that the strip of material (once again thismay be, for example, non-woven fabric of the SMS type) extends beyondthe base omega-shaped configuration represented in FIGS. 1 to 3 so as topresent, as ideal extension of one of the distal branches 14, a furtherbranch 22, which extends in the form of a bridge connecting the twodistal branches 14, it being connected thereto by layers of glue 24.

In this case, the modes of application on the product D (exemplified inFIG. 5) envisage application of a layer of glue 20—which this timeextends with continuity so as to give rise to the final configuration ofconnection represented in FIG. 6. This configuration proves particularlyfirm in so far as the connection between the two end parts of thesanitary product is ensured by two parallel flexible elements defined bycorresponding branches of the original omega-shaped element.

In this case, the fastening of the flap located on the sides of thefinished product is obtained by applying a layer of glue (for instance,of an evergreen type), designated by 26, which is deposited in theregion or area of the base branch 10 delimited by the projection thereonof the edges of the elbows that connect the intermediate stretches 12with the distal stretches 14 so as to render fastening of the flaps seton the sides of the diaper releasable and refastenable.

The element illustrated in FIGS. 4 to 6 presents the further advantagerepresented by the fact that it appears right from the start as a closedelement with a tubular structure. This means that it is possible, inthis case, to prevent application of provisional seal formations for theconservation of the closed-packet structure during processing.

The additional branch 22 (which, like the base branch 10, is to be cutout in the median plane X-X) may in itself also consist of a materialdifferent from the material constituting the remaining parts of theelement 1.

This possibility of differentiation is further shown in the variant ofFIGS. 7 to 9 (and also in the solution, which is, as a whole, similar,represented in FIGS. 10 to 12).

The embodiments referred to in FIGS. 7 to 12 are the currently preferredembodiments of the invention. These are aimed at bestowing on theelement 1 characteristics of releasability and refastenability.

In this case, in fact, the material constituting the branch 22 (which ishere to form an element in itself associated to an omega-shapedstructure of the type represented in FIGS. 4 to 6) and thecharacteristics of the material constituting the remaining part of theelement 1 (namely, the distal stretches 14 thereof are differentiated insuch a way that the said two elements present characteristics ofdisengageable and re-engageable connectability. These arecharacteristics that can be obtained by bestowing on these complementaryelements the characteristics of the parts of a fastening of a microhook(hook-and-loop) mechanical type, or of a fastener of the type commonlyreferred to as Velcro fastener.

For instance, the branch 22 can be configured in such a way as to carryhook-like parts, which are designed to engage corresponding loop-likeparts provided in the distal branches 14.

The said loop-like parts may either be present on the distal branches 14or form part of the distal branches 14 themselves: for instance, thesaid distal branches 14 may be made—in a way in itself known—in the formof a non-woven fabric comprising fibres which are sufficiently loose anddisconnected from one another as to form loops which can be engaged bythe hooks' carried by the branch 22.

As may be seen in FIG. 9, the connection structure that may be obtainedis substantially similar to the one already illustrated in FIG. 6 (itwill be noted simply that FIGS. 6 and 9 are specular with respect to oneanother), with the important difference represented by the fact that theconfiguration of connection represented in FIG. 9 is uncoupleable. Thebranch portion 22 connected to one of the end parts of the sanitaryproduct is in fact selectively disengageable from the distal branch 14to which it normally adheres, at the same time with the possibility ofre-engagement according to the modalities already defined as “releasableand refastenable”.

In this case, fastening of the flaps located on the sides of thefinished product is obtained thanks to the releasable and refastenableconnection of the branch portion 22 and the base-branch portion 10,which are comprised in the flaps.

FIGS. 10 to 12 refer to a solution that is, as a whole, identical to theone represented in FIGS. 7 to 9, with the difference represented by thefact that, instead of being made of a single piece, the branch 22illustrated in FIGS. 10 to 12 is made up of two separate portions, eachof which is to be selectively connected to a respective distal branch14.

As envisaged in the case of the embodiment illustrated in FIGS. 1 to 3,also for this embodiment it is possible to resort to provisional-sealformations 23 for fixing the intermediate stretches 12 to thecorresponding distal stretches 14, thus rendering the element similar toa closed element, and hence, not exposed to any adverse phenomena offlapping. As in the case described previously, the said provisional-sealformation can be made with the application of a spot of evergreen glueor pressure-sensitive glue or by means of a thermo-mechanical-weldingspot (heat sealing).

The embodiment illustrated in FIGS. 10 and 12 affords the advantagerepresented by the fact that, since the branch 22 has a discontinuity inthe central portion of the element 1 (hence along the cutting line X-X),it enables a saving in costs to be achieved as compared to theembodiment illustrated in FIGS. 10 to 12 (Velcro-type material issomewhat costly).

As in the embodiment illustrated in FIGS. 1 to 3, a third layer of glueof the evergreen type, designated by 25, is deposited on the side end ofthe product D opposite to the base branch 10, in the region or areadelimited by the projection of the edges of the elbows that connect theintermediate stretches 12 with the distal stretches 14 on said side end,to obtain the releasable and refastenable fastening structure of theflaps located on the sides of the diaper.

Furthermore, in the embodiment illustrated in FIGS. 10 to 12 and in theconditions represented in FIG. 12, the branch 22 (which may consist ofquite a rigid element, above all if it is made up of the part providedwith microhooks of a structure of the homologous type) is altogetherhidden with respect to the outside, a result that is not obtained in thecase of the solution referred to in FIG. 9.

Also in the embodiments of FIGS. 7 to 12, the distal branch 14 and theintermediate branch 12 provide for shielding of the flap, ensuring acontinuous and delicate contact (soft touch) on the hips of the user.

FIGS. 13 to 15 illustrate a further development of the fastening element1 of a disengageable and re-engageable type, already illustrated withreference to FIGS. 7 to 12.

In the embodiment illustrated in FIGS. 13 to 15, the configuration ofconnection of the distal branches 14 and of the branch 22 is reversedwith respect to the previous cases. In this case, instead of carryingthe hook formations of the microhook fastening structure, the branch 22carries (i.e., incorporates) the parts with loops, whilst the hooks arecarried by elements 14′ applied by means of respective layers of glue14″ on the distal branches 14 of the omega-shaped base structure.

In this case, considering the configuration after cutting andsplaying-out of the product D along the waist line, an element of themicrohook fastening system is effectively exposed along the flapslocated on the sides: this is, however, the part 22 that carries theloops, whilst the part that carries the microhooks is altogether hiddenwithin the fastening element 1.

As in the embodiment illustrated in FIGS. 4 to 6, fastening of the flapslocated on the sides of the finished product is obtained by applicationof a layer of evergreen glue, designated by 26, deposited in the regionor area of the base branch 10 delimited by the projection thereon of theedges of the elbows that connect the intermediate stretches 12 to thedistal stretches 14 so as to obtain the releasable and refastenablefastening of the flaps located on the sides of the diaper.

FIGS. 16 to 18 refer to a solution that is, as a whole, identical to theone represented in FIGS. 13 to 15, with the difference represented bythe fact that, instead of being made of a single piece, the branch 22illustrated in FIGS. 16 to 18 is made up of two separate portions, eachof which is designed to be selectively connected to a respective distalbranch 14′.

As envisaged for the embodiment illustrated in FIGS. 1 to 3 and 10 to.12, also in the case of this embodiment a provisional-seal formation 23fixes the intermediate stretches 12 to the corresponding distalstretches 14, so that the element may be likened to a closed element,and hence one not exposed to the negative phenomena of flapping. As inthe cases previously described, said provisional-seal formation can beobtained with the application of a spot of evergreen glue orpressure-sensitive glue or by means of a thermo-mechanical-welding spot(heat sealing).

The embodiment illustrated in FIGS. 16 and 18 affords the advantagerepresented by the fact that, since the branch 22 has a discontinuity atthe central portion of the element 1 (hence along the cutting line X-X),it enables a saving in costs to be achieved with respect to theembodiment illustrated in FIGS. 13 to 15.

As in the embodiment illustrated in FIGS. 1 to 3 and 10 to 12, a thirdlayer of glue of the evergreen type, designated by 25, is deposited onthe side end of the product D opposite to the base branch 10, in theregion or area delimited by the projection of the edges of the elbowsthat connect the intermediate stretches 12 to the distal stretches 14 onsaid side end, in order to obtain releasable and refastenable fasteningof the flaps set on the sides of the diaper.

Also in the embodiments illustrated in FIGS. 13 to 18, the distal branch14 and the intermediate branch 12 provide for shielding of the flaps,ensuring a continuous and delicate contact (soft touch) on the hips ofthe user.

There now follows a more detailed description of FIGS. 19 and 20. As hasalready been said, the figures in question refer to a particularlypreferred applicational solution, in which the process of fabrication ofthe strip-like material designed for being segmented to obtain thefastening elements 1 is integrated (basically as a set of preliminaryoperations) in the process of application of the elements 1 themselveson the semi-finished pieces D′ which are to give rise—via the sequenceof operations of folding to form a V (station 100) and of cutting(station 102) already described previously—to the products D.

It will, however, be appreciated that, albeit constituting a currentlypreferred choice, the fact of integrating the process of fabrication ofthe elements 1 with the process of application thereof and with theprocess of fabrication of the products D does not constitute in any wayan imperative choice.

The elements 1 are suited for being made in the form of a semi-finishedproduct consisting of a strip-like material that can be cut to length insuccessive lengths (i.e., segmented) with a view to its application onthe products D. The aforesaid semi-finished product constitutes aproduct in itself, which can be manufactured separately and then besupplied to the subjects that carry out the process of application ofthe elements themselves in the process of fabrication of the products D.

As will emerge more clearly from what follows, the solutions illustratedin FIGS. 19 and 20 refer principally (but not exclusively) to thefabrication and application of fastening elements 1 corresponding to theembodiments illustrated in FIGS. 7 to 9 and 10 to 12, respectively.

The aforesaid solutions thus present various elements in common. Itfollows that, in the absence of specific indications aimed atdistinguishing one solution from another, what has been said withreference to one solution applies directly also to the other.

Thus, in both of FIGS. 19 and 20, there may be seen the chain ofsemi-finished pieces D′ already described extensively previously, fed infrom the left to the right and from the bottom upwards. This chain ofsemi-finished pieces D′ is here assumed to be formed, according to knowncriteria, by equipment that is likewise known, and hence such as not torequire a more extensive description herein.

For reasons of completeness it is recalled that, in the solutionillustrated herein by way of example, the semi-finished pieces D′ areassumed as already presenting the sandwich structure (topsheet TS andbacksheet BS with interposition of an absorbent layer) describedpreviously. Even though this solution is widely preferred, there arecertainly not excluded from the scope of the invention solutions inwhich the aforesaid sandwich structure is obtained in a momentsubsequent to or concomitant with the operations described here.

In FIG. 19, the reference 114 designates a station for intermittentapplication of glue. The station 114 is designed for applying on thechain of semi-finished pieces D′—in exactly determined positions atregular distances apart, corresponding to the positions in which it isdesired to arrange the fastening elements 1—areolae of glue which formin practice the layer of glue designated by 18 in FIGS. 7 to 12.

The characteristics of the station 114 and of the glue there applied(for example a glue of the hot-melt type) are to be considered certainlyknown to the person skilled in the sector of manufacture of absorbentsanitary products.

The station 114 operates in the proximity of the margin of the chain ofsemi-finished pieces D′ designated by F1.

Once again in FIG. 19, the reference 114′ designates a further stationfor the intermittent application of glue. The station 114′ is designedfor applying on the chain of semi-finished pieces D′—in exactlydetermined positions at regular distances apart, corresponding to thepositions in which it is desired to arrange the fastening elements1—areas of glue that, in practice, form the layer of glue designated by25 in FIGS. 1 to 3 and FIGS. 10 to 12.

Also the station 114′, like the station 114, operates in the proximityof the margin of the chain of semi-finished pieces D′ designated by F1.

In the solution illustrated in FIG. 20, there is envisaged the presenceof a station homologous to the station 114, designated by 116, whichoperates in the proximity of the margin designated by F2. Also thestation 116 applies on the chain of semifinished pieces D′—in exactlydetermined positions at regular distances apart, corresponding to thepositions in which it is desired to arrange the fastening elements1—areas of glue. In this case, these are areas of glue that form thelayer of glue 20.

Once again in FIG. 20, the reference 116′ designates a further stationfor the intermittent application of glue (represented by a dashed line).If present, the station 116′ is designed to apply on the chain ofsemi-finished pieces D′—in exactly determined positions at regulardistances apart, corresponding to the positions in which it is desiredto arrange the fastening elements 1—areas of glue that, in practice,form the layer of glue designated by 26 in FIGS. 16 to 18.

Also the station 116′, like the station 116, operates in the proximityof the margin of the chain of semi-finished pieces D′ designated by F2.

In both of FIGS. 19 and 20 the reference 118 indicates a source—this istypically of a reel-type unwinder with the function of fast change ofthe feeding reel—from which there is wound off a strip 120 of material,such as a non-woven fabric.

The material constituting the strip can present a loop structure thatconfers thereon the possibility of constituting—without furthertreatment—the part provided with loops of a hook-and-loop fasteningconfiguration.

In a bending station 122—of a known type—the strip 120 is subjected toan operation of bending to form a C basically corresponding to theformation of the two distal branches 14 (see once again FIGS. 7 and 10)and to the upturning thereof on the parts of the strip 120 designed forsubsequently forming the intermediate branches 12 of the element 1.

The reference 124 designates a station used for the embodimentillustrated in FIGS. 1 to 3, 10 to 12 and 16 to 18 for application, onthe C-shaped strip formed in the station 122,—in exactly determinedpositions, at regular distances apart,—the provisional-seal formation23.

As already described previously, the aforesaid provisional-sealformation 23 entails the establishing of a “technical” connection ortacking (i.e., a non-permanent connection which will be absent in thefinished product) between the free ends of the distal branches 14 andthe body part of the strip on which said branches are folded back, thepurpose being to prevent the aforesaid free ends and/or distal branches14 as a whole from possibly lifting up, even marginally, from the restof the strip, and so hindering the subsequent operations of treatmentdescribed in what follows.

The aforesaid (preferred, but non-imperative) provisional-seal formationis also obtained according to known criteria, for instance with theapplication of a so-called technical glue or with a welding spotobtained using systems of thermo-mechanical welding (heat sealing) and,in particular, ultrasonic-sealing systems. By its very nature, theadhesive character of a technical glue is not permanent and ceases to beeffective after a certain period of time. Glues of this type are knownin the art. For instance, the experiments conducted by the presentapplicant show that, in the context of the present invention,particularly effective is the use, as technical glue, of the product AL11 available from, for example, Savaré I. C. S.r.I. of Milan.

The strip, in the position where it is bent to form a C, is sent on to astation for dispensing glue 126, which applies, on the body of thestrip, two strips of glue (no longer technical, but permanent, forinstance of the hot-melt type) corresponding to the layers designated by16 in FIGS. 7 to 12.

At this point, the strip advances through a further bending station 126,which (see once again for reasons of clarity FIGS. 7 and 10) performsthe upturning of the distal branches 14 and of the intermediate branches12 on the body (i.e., on the central part of the strip).

In practice, the station 126 performs a further operation of bending inthe form of a C with the concavity opposite to that of the operation ofbending carried out in the station 122, thus achieving the desiredgeneral omega-shaped configuration and bringing about stable connectionof the intermediate branches 12 with the central part, i.e., with theomega-shaped base branches 10.

On the structure thus obtained, the element 22 is then applied, which,in the embodiment described herein, carries hook-like parts that canengage in a removable way corresponding loop-like parts present—eitherintrinsically or in so far as they are applied—on the distal branches 14of the remaining part of the fastening element.

In the case of the embodiment illustrated in FIGS. 7 to 9, the element22 is made of a single piece.

The corresponding application equipment, represented in FIG. 19, thuscomprises a dispensing reel 128, from which the corresponding strip-likematerial is wound off towards a roller-type connection station 130. Herethe strip carrying the hooks 22 is applied against the distal branches14, which provide the loops, so achieving a configuration of firm butseparable connection. As has been seen, it is this that enables releaseand refastening of the waistline of the product D along the flapslocated on the sides.

In the case of the embodiment illustrated in FIGS. 10 to 12, the element22 is made up of two pieces, separated by the discontinuity that enablesthe layer of glue 25 to adhere centrally to the base branch 10 of thefastening element 1. The corresponding application equipment,represented in FIG. 20, thus comprises two dispensing reels 128 a and128 b, from which the two portions of strip-like material that are tomake up the two branches of the layer 22 are wound off in the directionof the roller-type connection station 130. Here the two portions ofstrip carrying the hooks 22 are applied against one and the other of thedistal branches 14, which provide the loops, also in this case, forminga configuration of firm but separable connection.

In the one case (FIG. 19) and in the other case (FIG. 20), the compositestrip thus obtained advances towards an application station 132, inwhich the strip in question undergoes segmentation so as to form theindividual fastening elements 1, which are to be applied by the station114 on the chain of semi-finished pieces D′ in positions correspondingto the adhesive areas.

The application station 132 is usually shaped so as to impart on thelengths that are to form the elements 1 a rotation of 90°. This rotationis designed to take into account the fact that the composite stripcoming out of the connection station 130 advances lengthwise, i.e., withthe ideal plane of cross section, represented in FIGS. 7 and 10,oriented in a direction orthogonal to the direction of advance of thestrip, which is collinear with the direction of advance of the chain ofsemi-finished pieces D′.

At the same time, the elements 1 are applied on the chain ofsemi-finished pieces D′ with the plane X-X of FIGS. 7 and 10 orientedalong the homologous line of action of the cutting station 102, i.e., ina direction transverse to the direction of advance of the said chain.

Stations for segmentation and rotation, which have the characteristicsdescribed above and which may likewise allow for the considerabledifference in speed of advance between the strip coming out of theroller-type connection station 130 and the chain of semi-finished piecesD′, are well known in the art, as is witnessed, for example, by thedocuments EP-A-0 943 395 or EP-A-0 997 123. The said documents, to whichreference may be made for a more detailed description of the station132, are both filed in the name of the holder of the present patentapplication.

At this point, the chain of semi-finished pieces D′, which carry theelements 1 applied at the margin F1, is made to advance towards thestation 100, which performs the action of closing to form a V, asalready described.

In particular, the representation of FIG. 19 refers specifically to anembodiment in which the sides or faces of the elements 1 which are to beapplied against the margin F2 of the chain of semi-finished pieces D′have been previously adhesive-coated, thus rendering them of theself-adhesive type. In this way, there is avoided the need to depositcorresponding areas of glue along the margin F2 of the chain ofsemi-finished pieces D′.

This result (pre-adhesive-coating) can be obtained—according to knowncriteria—at the level of the application station 132, for instance byenvisaging the presence of an applicator assembly (not illustrated inthe drawings), which applies—before or after segmentation of the stripfrom which the elements 1 are formed—a film of glue on the side or faceof the element that is to undergo pre-adhesive-coating, and byconfiguring the gripping elements of the application station 132 so thatthey may perform on the elements 1 the necessary function of picking-upand transfer, so preventing any undesirable adhesive connection with theelements 1 themselves. This result can be obtained, for example, byproviding the application station 132 with ice-film gripping elements.

It goes without saying that the pre-adhesive-coating can beprovided—also here by resorting to measures in themselves known—on bothof the faces or sides of the elements 1, thus rendering superfluous theapplication of areas of glue along both of the margins F1 and F2 of thechain of semi-finished pieces D′.

The choice of one particular solution rather than another is evidentlydictated by the specific applicational requirements. Recourse to thepre-adhesive-coating (on one or both of the sides) has the undoubtedadvantage of rendering less critical the synchronization between theapplication station 132 and the movement of advance of the chain ofsemi-finished pieces D′. It is evident that, in the case of thepre-adhesive-coating, a synchronization such as to prevent anexcessively rough positioning of the elements 1 is sufficient, in viewof the fact that it is no longer necessary to ensure the level ofprecision such as to cause each element 1 to be positioned exactly, in acentred way, on a corresponding areola of glue.

Once again with reference to FIG. 19, the strip 22 is anchored on thehomologous borders (still connected together—in so far as they aredesigned to be separated only subsequently by the action of the cuttingunit 102) of the side ends facing two semi-finished pieces D′ that areadjacent in the chain, by means of an adhesive layer present on the backof said strip 22, i.e., appropriately applied thereon by the station forintermittent application of glue 131, which is of the same type as thestation 114.

With reference to FIG. 20, the strip 22 is anchored on said homologousborders of the side ends facing two semi-finished pieces D′ adjacent inthe chain, by means of the application on the topsheet TS to which thelayer 22 is to be connected (see in this regard FIGS. 8 and 11) of areasof glue corresponding to the layers designated by 20 in FIGS. 8 and 11.Given the firm and precise anchorage of the element 1 on the chain ofsemi-finished pieces D′ obtained by means of the station 132, the glueof the layer 20 can be applied either on the back of the layer 22 by thestation 131 (see in this regard FIG. 19) or on the topsheet TS to whichthe layer 22 is to be connected (see in this regard FIG. 20).Furthermore, precisely on account of its “closed” configuration, theelement 1 proves stable in shape and free from any phenomena offlapping, so that, even when the station 100 is made to function at ahigh speed, it is possible to rely on the fact that the areas of glue20—whether applied on the topsheet of the semi-finished pieces, orapplied on the back of the strip 22—will always end up being positionedexactly between these two elements, so as to be able to perform itsfunction correctly.

The semi-finished pieces D′, which are at this point closed so as toform a V shape, advance towards the cutting station 102, where,according to the operating procedure described previously, theindividual products D are formed.

Preferentially, between the closing station 100 and the cutting station102 there is present a station 134 designed for clinching andconsolidating, with an action of compression, the connection between thefastening elements 1 and the portions of topsheet TS, between which eachelement 1 is comprised in the finished product D (here again see, forexample, FIGS. 8 and 11).

It will be appreciated that this consolidating action is performed alsoin regard to the microhook connection established between the layer 22and the distal branches 14, as well as in the case of the embodimentillustrated in FIGS. 10 to 12, in regard to the connection between theadhesive layer 25 and the central part of the base branch 10.

In a currently preferred embodiment, the station 134 has a generalconfiguration that may be likened to that of a belt press with amotor-powered closed-loop mobile pressing formation, which may basicallybe likened to a track that presses the products D with its activebranch, located in the bottom position and mobile in a way concordantand synchronized with the chain of products D.

The action of pressure may be applied either against a plane of sliding,on which the products D slide, or, in a preferred way, against anunderlying belt conveyor (not visible in the drawings), which ensuresconveying of the products D, i.e., against a track formation that isaltogether identical to what may be seen in the drawings, but locatedunder the plane of advance of the products D.

In a preferred way, the track formation or formations in question haveteeth 134 a in positions corresponding to those occupied by themicrohook connection between the layer 22 and the distal branches 14,i.e., in the case of the embodiment illustrated in FIGS. 10 to 12, ofthe connection between the adhesive layer 25 and the central part of thebase branch 10.

The track formations in question operate so as to apply the samevertical compressive pressures adequate for ensuring fastening of theflaps set on the sides, so preventing application on the remaining partsof the fastening element 1 of excessively strong vertical compressivepressures such as might squeeze them excessively. It will be appreciatedthat, by selectively adjusting the intensity of the action ofcompression exerted on the products D by the formation 134, it ispossible to regulate precisely (in the case of embodiments of the typeillustrated in FIGS. 9 to 12) the intensity of the connection betweenthe layers 22 and the distal branches 14. It is thus possible to adjustthe intensity of the reaction opposed by the elements 1 to any attemptto open the waistline of the products D that is precisely aimed atseparating the layers 22 and the distal branches 14 from one another.

The teeth 134 a make it possible to bestow on the element 1 (even beforeit arrives at the cutting station 102) the general hourglassconfiguration that may clearly be seen in FIGS. 2, 5, 8, 11, 14 and 17,which, after cutting of the element along the line X-X, lies at thebasis of the fastening (which may be releasable and refastenable,according to the criteria repeatedly referred to previously) of theflaps located on the sides of the product.

In other words, the teeth 134 a enable the appropriate connectionformation provided in the median plane X-X (layers of glue 25 or 26,central stretch of the microhook formations which operate in a positionhomologous to these layers of glue) to act between the borders B1, B2that are set facing one another.

FIGS. 21 and 22 are schematic illustrations of the possibility of usingthe fastening element 1 described previously (in any of the embodimentsconsidered) in the context of a process of fabrication of sanitaryproducts D in which the strip, web or chain of semi-finished pieces D′is constituted by semi-finished pieces connected together notcrosswise—as in the case of the solutions illustrated in FIGS. 19 and20—but lengthwise.

In a process of this type (which is at times referred to asmachine-direction process, i.e., one carried out in the direction of themachine), the various semi-finished pieces D′ advance lengthwise, i.e.,with their end parts aligned in the direction of advance, with the rearend of one semi-finished piece connected to the front end of thesemi-finished piece following it in the chain (see the top part of FIGS.21 and 22). Of course, “front” and “rear” here refer to the direction ofadvance of the chain (from the bottom upwards in FIGS. 21 and 22), andnot to the way in which the product D will be worn.

The various semi-finished pieces D′ of the chain are then separatedalong lines of cutting T using equipment basically similar to thecutting station 102 that may be seen in FIGS. 19 and 20 so as to giverise to the individual products D.

Also in this case, it must be assumed that the process of fabricationreferred to herein is in itself known in its essential terms. Thisapplies also to the final processing step (not explicitly illustrated inFIGS. 21 and 22), in which the individual products D obtained as shownin the top part of the aforesaid FIGS. 21 and 22 are closed to form a Uor a V in order to bestow thereon the desired pant-like configuration.

As regards the fabrication of the strip-like element from which theindividual fastening elements are obtained, it may be assumed that thealternative solutions represented in FIGS. 21 and 22 basically reproducethe solutions illustrated in FIGS. 19 and 20 up to the roller-typeconnection station 130.

From here, in the solutions illustrated in FIGS. 21 and 22, theaforesaid strip-like element passes into a station 134′, which has afunction basically similar to that of the station 134 of FIGS. 19 and20, i.e., that of pressing the strip-like element centrally in the planeX-X so as to bestow thereon the general hourglass pattern that may beseen in FIGS. 2, 5, 8, 11, 14 and 17. Of course, whilst the station 134of FIGS. 19 and 20 finds itself operating in a crosswise direction withrespect to the direction of advance of the chain of semi-finished piecesD′ (on which the elements 1 have been applied after being rotated by 90°in the station 132), the station 134′ of FIGS. 20 and 21 operates.lengthwise, and can be usefully made up of two ribbed counter-rotatingwheels or rollers, which impress the hourglass-shaped pattern on thestrip-like element that advances in the space or gap defined betweensaid wheels or rollers.

Set cascaded to the station 134′ is a cutting station 135, which—againoperating lengthwise—brings about the division of the strip-like element(which, in effect, can now be equated with the element 1) in the planeX-X, i.e., dividing the strip-like element 1 into two basicallysymmetrical parts.

The structure of the station 135 may basically be identical to that ofthe station 134′ just described. Indeed, the two stations 134′ and 135can be fused into a single station that performs both shaping to formthe hourglass configuration and cutting of the element 1 in the planeX-X.

From here, the two parts of the element 1 are sent on to the chain ofmoving semi-finished pieces D′ to be applied on the semi-finished piecesthemselves, one on the left-hand side F1 and one on the right-hand sideF2 of the chain in question. Of course, also in this case, the terms“right-hand” and “left-hand” are used in reference to the graphicrepresentation of FIGS. 21 and 22 and do not bear any direct relation tothe way in which the product D is worn.

Prior to being applied on the semi-finished pieces D′ (an operation thatis carried out via a machine which is basically similar to the station132 illustrated in FIGS. 19 and 20), the two branches or parts of thestrip-like element are segmented into lengths in a transverse cuttingstation, designated by 137.

FIGS. 21 and 22 show a solution in which, in the stretch between thelongitudinal cutting station 135 (i.e., for cutting along the plane X-X)and the cutting station 137 (usually one for each side of the chain ofsemi-finished pieces D′—even though it is possible to use a singlestation operating on both sides), the parts of the element 1 aresubjected to a rotation of 90°.

This rotation may be imparted on the elements elsewhere (for instance,in the station 132), but may not even be required at all if the element1 is already formed lengthwise, i.e., in the direction of advance of thechain of the semi-finished pieces D′, as illustrated (albeit in adifferent context) in FIGS. 19 and 20.

For the application of the individual elements 1 on the semi-finishedpieces D′ it is possible to adopt different solutions.

For example, FIG. 21 shows a solution in which there exit from thecutting stations 137 lengths which are as long as the individual element1 (or, rather, as long as the individual part of element 1) that is tobe applied on the lateral facing borders of the end parts of theindividual product D so as to close the individual product at both ofits side flaps.

In this case, on each side of the chain (F1 or F2), there is applied anindividual part of element 1 in a position which, after cutting has beenperformed along the line T, will correspond to the front end or rear endof the individual product D. In this case, the mode of application ofthe elements 1 is identical for each product D.

FIG. 22 illustrates, instead, a solution in which there exit from thecutting stations 137 lengths that are twice as long as the individualelement 1 (or, rather, twice as long as the individual part of element1) that is to be applied on the lateral facing borders of the end partsof the individual product D so as to close the individual product atboth of its side flaps.

In this case, on each side of the chain (F1 or F2), there is alternatelyapplied an ensemble made up of two parts cascaded with respect to oneanother, each of which will constitute a fastening element applied onthe front end or rear end of the individual product D—only after cuttinghas been performed along the line T. In this case, the procedure forapplication of the elements 1 is different and alternated for theproducts D; namely, one product D will come out with the fasteningelements 1 applied on the front end, whereas the next one will have thefastening elements 1 applied on the rear end.

Of course, it is also possible to modify the criterion represented inFIG. 22 by applying the piece of double length coming out of thestations 137, once on the side F1 and once on the side F2, with analternating pitch equal to the length of the individual product D.

Basically, the solutions illustrated in FIGS. 21 and 22 have in commonwith the solutions illustrated in FIGS. 19 and 20 the idea of making thefastening elements 1 starting from a strip-like element.

In the solutions illustrated in FIGS. 21 and 22 there is envisaged theoperation of cutting (in the station 135) the aforesaid strip-likeelement in the intermediate plane X-X so as to separate the two parts ofthe fastening element 1 prior to its application on the correspondingsanitary product D. The aforesaid parts of fastening element 1 are thenapplied to each of the two opposite longitudinal sides F1, F2 of thechain of semi-finished pieces.

In the solution illustrated in FIG. 21, this is done by applying theaforesaid parts of fastening element 1 in the form of segments, each ofwhich is associated to one end of a respective semi-finished piece D′comprised in said chain.

In the solution illustrated in FIG. 22, this is obtained, instead, byapplying the aforesaid: parts of fastening element 1 in the form ofsegments (of double length), each of which is associated to the end oftwo semi-finished pieces D′ of the chain. The subsequent segmentation ofthe chain along the lines indicated by T, leads to the separation of thesemi-finished pieces D′ connected to one another at said end parts, withthe formation of individual products D. The operation of segmentationlikewise divides the aforesaid double segments into two portions, eachof which is associated to one end of a respective product D.

As has already been said, the final processing step, in which theindividual products D obtained as represented in the top part of theaforesaid FIGS. 21 and 22 are closed to form a U or a V in order tobestow thereon the desired pant-like configuration, is not explicitlyillustrated in FIGS. 21 and 22. The same applies as regards theapplication of the area of glue or the formation of the welding areasthat secure the fastening elements 1 on the ends of the semi-finishedpieces D′. For this purpose, there are applied, with the necessarymodifications made, the same technical solutions already described withreference to FIGS. 19 and 20. This applies also as regards the possiblepre-adhesive-coating of the elements 1.

The solutions described previously with reference to FIGS. 19 to 22 thusenable production of an absorbent sanitary product which can be wornlike a pair of pants and which comprises two end parts that present, oneach side of the product, homologous lateral facing borders, which canbe connected together so as to define the waist line and the passage forlegs of the product itself. On each side of the product, the aforesaidlateral facing borders are connected together by one of the aforesaidtwo parts or halves of a fastening element 1 of the type described. Eachof the parts or halves in question in turn comprises a base branch 10,connected to one of the aforesaid end parts of the product D, and adistal branch 14, connected to the other of the end parts of the sameproduct D, completing its fastening on the waist. The base branch 10 andthe distal branch 14 are connected together according to a generalbook-like configuration open towards the inside of the sanitary product,so that the tensile stresses exerted along the waist line of thesanitary product are sustained as a result of the connection between thebase branch 10 and the distal branch 14.

FIG. 23 to 25 show a still further possible variant mode of fabricationof the fastening element described herein. This variant is intended totake into account the fact that absorbent sanitary products of the“training pant” or “undergarment” type can be used with increasedcomfort if the possibility exists of inspecting the product while beingused (i.e., worn) and/or adapting the “fit” of the product to the wearerby selectively increasing/decreasing the length of the waist line.

Specifically, FIGS. 23 to 25 show how the embodiment shown of FIGS. 16to 18 can be modified to permit the product to be opened and refastened,while also providing the possibility of varying the length of the waistline of the product.

In the embodiment shown this result is achieved by making it possibleto:

-   -   selectively vary (as shown by way of example at the lower        left-hand side of FIG. 25) the position where the hook element        22 engages the distal branch 14 of the fastening element 1 to        which the hook element is associated, and/or    -   selectively vary (as shown by way of example at the upper        right-hand side of FIG. 25) the position where the hook element        22 in question engages the opposed outer surface of the facing        side edge (or flap) of the product.

To achieve the former result, the distal branch 14 to which the hookelement 22 is currently associated is extended as indicated at 140, sothat each distal branch 14 is in fact longer that the homologousintermediate branch 12: this fact can be promptly appreciated by directcomparison of FIGS. 16 and 17, on the one side, and FIGS. 23 and 24, onthe other side.

Stated otherwise, in the embodiment shown the connection structure ofthe releasable and refastenable type (i.e., the hook element 22) isadapted to be associated to the distal branch 14 at a plurality ofdifferent positions, whereby the length of the waist line of saidabsorbent sanitary product 1 is selectively adjustable. Preferably, thisis achieved simply by making the distal branch 14 longer (as shown at140) than said the connection structure 22 of the releasable andrefastenable type.

In that way, the product 1 may be easily opened (thus having i.a. thepossibility of inspecting its state of use) by simply pulling thebacksheet/topsheet portion carrying the hook element 22 in order toseparate the hook element 22 from the underlying distal branch 14 towhich the hook element 22 is currently associated.

Once opened, the product may be re-closed (refastened) with thepossibility of coupling the hook element 22 to the distal branch 14 at aposition as schematically shown in dotted lines in FIG. 25, that is aposition different from the position where the hook element 22 wasoriginally coupled to the distal branch 14. In that way the length ofthe waist line of the product (i.e., the “fit” to the wearer) can beselectively varied.

This typically occurs by arranging the hook element 22 farther away fromthe intermediate branch 12, which leads to increasing the length of thewaist line and giving the product a “looser” fit to the wearer's body.

The latter result referred to in the foregoing may be achieved by meansof a further “hook engageable” (i.e., loop) surface as indicated byreference numeral 1000 in FIGS. 24 and 25. Specifically, the furtherhook engageable surface 1000 is provided in correspondence with theouter side of the backsheet/topsheet pair carrying the base branch 10.The hook engageable surface in question may be provided in the form of aloop insert applied, e.g., by gluing, the outer side of thebacksheet/topsheet pair carrying the base branch 10 or by making, atleast locally, the backsheet element BS of the backsheet/topsheet pairin question in the form of a loop material adapted for engagement by thehook element 22.

By providing the surface 1000, the product, once opened, may bere-closed (refastened) with the possibility of coupling the hook element22 to the surface 1000 as schematically shown in chain line in FIG. 25.This is again a position different from the position where the hookelement 22 was originally coupled to the distal branch 14, thus onceagain giving the possibility of selectively varying the length of thewaistline of the product.

In this latter case, this occurs by arranging the hook element 22 overthe opposed outer surface of the facing side edge (or flap) of theproduct, which leads to decreasing the length of the waist line andgiving the product a “tighter” fit to the wearer's body.

Stated otherwise, according to the latter feature considered, in eachsaid pair of the homologous facing side edges that can be connectedtogether to close the product along the waistline of the wearer:

-   -   on one facing edge, the distal branch 14 of the fastening        element 1 has associated therewith a microhook fastener 22, and    -   the other facing edge has a surface 1000 adapted to be engaged        by the microhook fastener 22 in a releasable and refastenable        relationship.

The microhook fastener 22 is thus adapted to be associated to the facingside of a homologous end part at a plurality of different positions toselectively adjust the length of the waist line of said absorbentsanitary product 1.

The other facing edge in question may either carry an element with loopsadapted to be engaged by the microhook fastener 22 or be made of amaterial with loop structure. In this latter case, the loops of the loopstructure constitute the loops that can be selectively engaged by thehooks of the microhook fastener 22.

Those of skill in the art will promptly appreciate that while thecombination of the features of i) extending the distal branches 14 andii) providing the surface 1000 represents a preferred embodimentpermitting the length of the waist line of the product to be bothincreased and decreased to a larger extent, the possibility exists ofresorting even to just either of those features.

Similarly, those of skill in the art will promptly appreciate thateither or both of these features can be applied to embodiments of thearrangement described herein different from that shown in FIGS. 16 to18.

There has been described herein a fastening element that may beconfigured as a sort of closed packet, free from any folds or similarconfigurations that might open out at the moment of cutting, transferand positioning of the element on the structure of absorbent articles,such as diapers. The element in question preferentially has anomega-shaped base structure, obtained, once again preferentially, withthe use of a single material for the principal constituent element.

There is thus obtained a fastening element which, thanks to thestructure and to the material used for the main constituent element,makes it possible to obtain a continuous and delicate contact (softtouch) on the hips of the user, so preventing the risk of causing anyirritation or cutting of the skin.

Also described herein is the possibility of making an absorbent sanitaryproduct which can be worn like a pair of pants, with the flaps locatedon the sides closed, but with the possibility of being opened andrefastened, in which the user is altogether prevented from forcing, bygripping the free flaps, the connection between the parts of thefastening element (in particular in the versions in which this isprovided for being refastenable), so causing the undesirable release ofthe waist line of the product.

All of the above U.S. patents, U.S. patent application publications,U.S. patent applications, foreign patents, foreign patent applicationsand non-patent publications referred to in this specification and/orlisted in the Application Data Sheet, are incorporated herein byreference, in their entirety.

Of course, without prejudice to the principle of the invention, thedetails of fabrication and the embodiments may vary widely with respectto what is described and illustrated herein, without thereby departingfrom the scope of the present invention, as defined by the annexedclaims.

In particular, it will be appreciated that the details of implementationillustrated herein with reference to each given embodiment, areunderstood as being freely transferable to one or more of the otherembodiments illustrated. Furthermore, it will be appreciated that thesolutions of connection described herein with reference to mechanisms ofadhesive connection can be replaced by equivalent solutions, whichenvisage, for instance, the use of mechanisms of connection by means ofheat sealing and/or ultrasonic sealing.

1. A fastening element for absorbent sanitary products which can be wornlike a pair of pants, said products presenting a waist line and endparts which can be connected together at side edges so as to reclosesaid waist line of the product, the fastening element beingcharacterized in that: the element has a general omega shape, theelement comprising two parts that are basically symmetrical with respectto an intermediate plane, each of said parts comprising in turn: a basebranch, which can be connected to the first of said end parts; and adistal branch, which can be connected to the second of said end parts,said base branch and said distal branch being connected togetheraccording to a general book-like configuration, which opens towards theoutside of the element; dorsal parts of said book-like connectingconfigurations between said base branch and said distal branches of saidbasically symmetrical parts are set at a distance apart with respect tosaid intermediate plane, said two basically symmetrical parts beingconnected together by means of said base branch so as to form a singlebody, which can be cut in said intermediate plane in order to separatesaid two basically symmetrical parts, each of which is able to connecttogether mutually facing sides of the end parts of a respectiveabsorbent sanitary product; each of said two parts comprising anintermediate branch, which extends to connect said base branch and saiddistal branch; said intermediate branch being stably applied againstsaid base branch.
 2. The element according to claim 1, characterized inthat said base branch and said distal branch constitute different partsof a single laminar body.
 3. The element according to claim 1,characterized in that said base branch, said intermediate branch, andsaid distal branch constitute different parts of a single laminar body.4. The element according to claim 2, characterized in that said laminarbody is made of non-woven fabric.
 5. The element according to claim 1,characterized in that it comprises a further branch, which extends likea bridge connecting the distal branches of said two parts so as tobestow on said element the character of a single body, it being possiblefor said further bridge-like element to be cut in said intermediateplane.
 6. The element according to claim 5, characterized in that saidfurther branch is stably connected to said distal branches.
 7. Theelement according to claim 1, characterized in that said distal branchof said parts of the element carries associated thereto a connectionmember of the releasable and refastenable type.
 8. The element accordingto claim 7, characterized in that said connection member of thereleasable and refastenable type is adapted to be associated to saiddistal branch at a plurality of different positions, whereby the lengthof the waist line of said absorbent sanitary products is selectivelyadjustable.
 9. The element according to claim 8, characterized in thatsaid distal branch is longer than said connection member of thereleasable and refastenable type, whereby said connection member of thereleasable and refastenable type is adapted to be associated to saiddistal branch at a plurality of different positions along said distalbranch.
 10. The element according to claim 7, characterized in that saidreleasable and refastenable connection member includes a microhookfastener.
 11. The element according to claim 10, characterized in thatsaid microhook fastener comprises one element with hooks and one elementwith loops, which can engage said hooks and in that said element withloops is associated to said distal branch.
 12. The element according toclaim 10, characterized in that said distal branch is constituted by amaterial with loop structure including loops that can be selectivelyengaged by the hooks of said microhook fastener.
 13. The elementaccording to claim 10, characterized in that said microhook fastenercomprises one element with hooks and one element with loops, which canbe engaged by said hooks and in that said element with hooks isassociated to said distal branch.
 14. The element according to claim 13,characterized in that said element with hooks is associated by means ofgluing to said distal branch.
 15. The element according to claim 1,characterized in that it comprises, in said intermediate plane, aformation of connection which can act between said mutually facing sideedges, so obtaining products with closed flaps located on the sides. 16.The element according to claim 15, characterized in that said connectionformation is of a releasable and refastenable type.
 17. The elementaccording to claim 15, characterized in that said connection formationis chosen in the group constituted by: an adhesive layer; and amicrohook-fastening-system formation.
 18. A process for making afastening element according to claim 1, characterized in that itcomprises the operations of: providing a strip-like body; shaping saidstrip-like body according to a general C shape, with the end of said Cshape constituting said distal branches of said two basicallysymmetrical parts of the element and the central part of said C shapedefining, at least in part, said base branch.
 19. An absorbent sanitaryproduct which can be worn like a pair of pants, comprising two endparts, which have, on opposite sides of the product, pairs of homologousfacing side edges that can be connected together so as to define thewaist line of the sanitary product, said facing edges being connectedtogether on each of said sides of the product by the base branch and bythe distal branch of one of said two basically symmetrical parts of atleast one fastening element according to claim
 1. 20. The product ofclaim 19, characterized in that, in each said pair of homologous facingside edges that can be connected together: said distal branch on onefacing edge has associated therewith a microhook fastener; and the otherfacing edge has a surface adapted to be engaged by said microhookfastener in a releasable and refastenable relationship, whereby saidmicrohook fastener is adapted to be associated to the facing side of ahomologous end part at a plurality of different positions to selectivelyadjust the length of the waist line of said absorbent sanitary product.21. The product according to claim 20, characterized in that said otherfacing edge carries an element with loops adapted to be engaged by saidmicrohook fastener.
 22. The product according to claim 20, characterizedin that said other facing edge is made of a material with loopstructure, the loops of said structure constituting the loops which canbe selectively engaged by the hooks of said microhook fastener.
 23. Afastening element for absorbent sanitary products which can be worn likea pair of pants, said products presenting a waist line and end partswhich can be connected together at side edges so as to reclose saidwaist line of the product, the fastening element being characterized inthat: the element comprises two parts that are basically symmetricalwith respect to an intermediate plane, each of said parts comprising inturn: a base branch, which can be connected to the first of said endparts; and a distal branch, which can be connected to the second of saidend parts, said base branch and said distal branch being connectedtogether according to a general book-like configuration, which openstowards the outside of the element, the element having an additionalbranch, which extends like a bridge connecting the distal branches ofsaid two parts so as to bestow on said element the character of a singlebody, it being possible for said bridge-like element to be cut in saidintermediate plane; wherein dorsal parts of said book-like connectingconfigurations between said base branch and said distal branches of saidbasically symmetrical parts are set at a distance apart with respect tosaid intermediate plane, said two basically symmetrical parts beingconnected together by means of said base branch so as to form a singlebody, which can be cut in said intermediate plane in order to separatesaid two basically symmetrical parts, each of which is able to connecttogether mutually facing sides of the end parts of a respectiveabsorbent sanitary product; each of said two parts comprising anintermediate branch, which extends to connect said base branch and saiddistal branch; said intermediate branch being stably applied againstsaid base branch.
 24. The element according to claim 23, characterizedin that said further branch is stably connected to said distal branches.25. The element according to claim 23, characterized in that said distalbranch of said parts of the element carries associated thereto aconnection member of the releasable and refastenable type.
 26. Theelement according to claim 25, characterized in that said connectionmember of the releasable and refastenable type is adapted to beassociated to said distal branch at a plurality of different positions,whereby the length of the waist line of said absorbent sanitary productsis selectively adjustable.
 27. The element according to claim 23,characterized in that it comprises, in said intermediate plane, aformation of connection which can act between said mutually facing sideedges, so obtaining products with closed flaps located on the sides. 28.The element according to claim 27, characterized in that said connectionformation is of a releasable and refastenable type.
 29. The elementaccording to claim 27, characterized in that said connection formationis chosen in the group constituted by: an adhesive layer; and amicrohook-fastening-system formation.